莺-琼盆地纵横波速度特征与AVO响应特征的关系研究

在莺-琼盆地,气层表现出了多种多样的AVO特征,有的为“Ⅲ”类,有的为“Ⅳ”类或“Ⅱ”类,有的偏离背景,有的与背景一致,这些复杂多样的AVO特征为应用AVO技术进行流体检测带来了较大的困难。为此,本文对近百口已钻井储层的AVO特征与纵、横波速度特征的关系进行了研究,并对产生这种关系的原因进行了详细分析,结果表明储层的纵横波速度的曲线形态和交会特征分别与储层AVO类型、截距与梯度交会特征有一定的对应关系,根据这种关系不仅在钻前可根据邻井的速度资料快速对目标区进行AVO流体检测的可行性进行分析,而且能在钻探失利后分析失利原因。最后利用该规律对莺-琼盆地某井钻后失利的原因进行了合理的解释。

Research on the relationship between P-wave and S-wave velocity characteristics and AVO response characteristics in Ying-Q iong basin

The gas layers in Ying-Qiong basin show a variety of AVO characteristics,with some of type III,type IV or type II,some deviating from the background,and some consistent with the background.These complex and diverse AVO characteristics make it difficult to apply AVO technology in fluid detection.To solve this problem,this paper studies the relationship between AVO characteristics and P-wave and S-wave velocity characteristics of nearly 100 drilled reservoirs,and analyzes the causes of this relationship in detail.The results show that the curve shape and intersection characteristics of reservoir P-wave and S-wave velocity have certain corresponding relations with reservoir AVO types,intercept and gradient intersection characteristics respectively.According to this relationship,not only the feasibility of AVO fluid detection in the target area can be analyzed quickly according to the velocity data of adjacent wells before drilling,but also the failure causes can be analyzed after a drilling failure.Finally,the reasons for a drilling failure in a well in Ying-Qiong basin is explained reasonably by using the law.